U.S. patent number 6,174,304 [Application Number 08/860,014] was granted by the patent office on 2001-01-16 for filling device for a needless injector cartridge.
This patent grant is currently assigned to Weston Medical Limited. Invention is credited to Terence Edward Weston.
United States Patent |
6,174,304 |
Weston |
January 16, 2001 |
**Please see images for:
( Certificate of Correction ) ** |
Filling device for a needless injector cartridge
Abstract
A needleless injector cartridge has an adaptor for introducing
fluid from a filling device into an orifice of the cartridge. The
adaptor has a frangible connection which is broken to allow removal
of the filling device after the cartridge is filled with the
fluid.
Inventors: |
Weston; Terence Edward
(Suffolk, GB) |
Assignee: |
Weston Medical Limited
(Suffolk, GB)
|
Family
ID: |
10766193 |
Appl.
No.: |
08/860,014 |
Filed: |
July 30, 1997 |
PCT
Filed: |
December 13, 1995 |
PCT No.: |
PCT/GB95/02913 |
371
Date: |
July 30, 1997 |
102(e)
Date: |
July 30, 1997 |
PCT
Pub. No.: |
WO96/19252 |
PCT
Pub. Date: |
June 27, 1996 |
Foreign Application Priority Data
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Dec 20, 1994 [GB] |
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9425642 |
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Current U.S.
Class: |
604/414; 604/201;
604/244; 604/82 |
Current CPC
Class: |
A61J
1/2096 (20130101); A61J 1/2044 (20150501); A61M
5/30 (20130101) |
Current International
Class: |
A61J
1/00 (20060101); A61M 5/30 (20060101); A61B
019/00 () |
Field of
Search: |
;604/49,131,181-183,187,200,201,218,220,225,240,244,68,70-72,82-88,411,414,416 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 201 638 |
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Nov 1986 |
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EP |
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0 328 504 |
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Aug 1989 |
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EP |
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0 412 621 |
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Feb 1991 |
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EP |
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0 526 772 |
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Feb 1993 |
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EP |
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0 737 484 |
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Oct 1996 |
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EP |
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824357 |
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Feb 1938 |
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FR |
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206 016 |
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Feb 1992 |
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HU |
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133435 |
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Sep 1971 |
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NL |
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WO95/03844 |
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Feb 1995 |
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WO |
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WO9524176 |
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Sep 1995 |
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WO |
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WO96/15821 |
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May 1996 |
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WO |
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WO96/28202 |
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Sep 1996 |
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WO |
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WO97/22375 |
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Jun 1997 |
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WO |
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WO98/12121 |
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Mar 1998 |
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WO |
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Primary Examiner: McDermott; Corrine
Attorney, Agent or Firm: McDermott, Will, & Emery
Claims
What is claimed is:
1. An adaptor for enabling a fluid to be introduced from an outlet
of a filling device into an orifice of a needleless injector
cartridge, comprising a first portion for engagement with the
cartridge, and a device-engaging second portion for engagement with
the filling device, whereby to maintain the outlet of the filling
device in fluid communication with the orifice of the cartridge,
the said first and second portions being connected to one another
by a frangible connection, comprising sealing means for effecting a
seal between the filling device outlet and the cartridge orifice,
wherein the sealing means comprises a sealing member having
opposite ends and respective conically tapering passages at said
opposite ends and means communicating the passages with one
another.
2. The adaptor according to claim 1, wherein the sealing means is
carried by support means connected to the said device-engaging
portion, so as to remain connected thereto when the said frangible
connection is broken.
3. An adaptor for enabling a fluid to be introduced from an outlet
of a filling device into an orifice of a needleless injector
cartridge, comprising a first portion for engagement with the
cartridge, and a device-engaging second portion for engagement with
the filling device, whereby to maintain the outlet of the filling
device in fluid communication with the orifice of the cartridge,
the said first and second portions being connected to one another
by a frangible connection, comprising sealing means for effecting a
seal between the filling device outlet and the cartridge orifice,
wherein the sealing means is carried by support means connected to
the said device-engaging portion, so as to remain connected thereto
when the said frangible connection is broken.
4. An adaptor according to claim 3 or 2, wherein said support means
comprises means for engagement with the distal end of the filling
device to align the filling device outlet with the cartridge
orifice.
5. A needleless injector cartridge in combination with an adapter
for enabling a fluid to be introduced from an outlet of a filling
device into an orifice of the cartridge, wherein the adaptor
comprises a first device-engaging portion whereby to maintain the
outlet of the filling device in fluid communication with the
orifice of the cartridge, and comprises a second portion for
engagement with the cartridge, the said first and second portions
being connected to one another by a frangible connection,
comprising sealing means engaged with the filling device outlet for
effecting a seal between the filling device outlet and the
cartridge orifice, wherein the sealing means comprises a sealing
member having respective conically tapering passages at opposite
ends thereof and means communicating the passages with one
another.
6. A cartridge/adaptor combination according to claim 5 wherein the
sealing means is carried by support means connected to the said
device-engaging portion so as to remain connected thereto when said
frangible portion is broken.
7. A cartridge/adaptor combination according to claim 6, wherein
said support means comprises means for engagement with the distal
end of the filling device to align the filling device outlet with
the cartridge orifice.
8. A needleless injector cartridge in combination with an adaptor
for enabling a fluid to be introduced from an outlet of a filling
device into an orifice of the cartridge, wherein the adaptor
comprises a first device-engaging portion whereby to maintain the
outlet of the filling device in fluid communication with the
orifice of the cartridge, and comprises a second portion for
engagement with the cartridge, the said first and second portions
being connected to one another by a frangible connection, wherein
the cartridge comprises a cartridge body with a longitudinally
slidable piston therein and wherein an abutment is provided within
the cartridge body for limiting movement of the piston away from
the cartridge orifice.
9. A needleless injector cartridge in combination with an adaptor
for enabling a fluid to be introduced from an outlet of a filling
device into an orifice of the cartridge, wherein the adaptor
comprises a first device-engaging portion whereby to maintain the
outlet of the filling device in fluid communication with the
orifice of the cartridge, and comprises a second portion for
engagement with the cartridge, the said first and second portions
being connected to one another by a frangible connection, wherein
the orifice of the cartridge is sealed with a frangible seal.
10. A cartridge/adaptor combination according to claim 9, wherein
the said frangible seal is capable of withstanding a pressure
differential of up to 900 mbar.
11. A method of reconstituting a lyophilized drug, wherein the drug
is stored in a needleless injector cartridge comprising a cartridge
body having an outlet orifice at one end thereof and a
longitudinally movable piston, the drug being located between the
piston and the outlet orifice, comprising:
(a) providing the needleless injector cartridge in combination with
an adaptor for enabling a liquid solvent to be introduced from an
outlet of a filling device into the orifice of the cartridge,
wherein the adaptor comprises a first device-engaging portion
whereby to maintain the outlet of the filling device in fluid
communication with the orifice of the cartridge, and a second
portion for engagement with the cartridge, the said first and
second portions being connected to one another by a frangible
connection; and
(b) introducing the liquid solvent introduced into the cartridge
through the outlet orifice to dissolve the lyophilized drug,
wherein longitudinal movement of the piston occurs.
12. A method according to claim 11, wherein longitudinal movement
of the piston is limited by stop means.
13. A method according to claim 11, wherein the outlet orifice of
the cartridge body is sealed with a frangible seal.
14. A method according to claim 13, wherein the said frangible seal
is capable of withstanding a pressure differential of up to 900
mbar.
15. A method of reconstituting a lyophilized drug, wherein the drug
is stored in a needleless injector cartridge comprising a cartridge
body having an outlet orifice at one end thereof and a
longitudinally movable piston, the drug being located between the
piston and the outlet orifice, comprising:
(a) providing the needleless injector cartridge in combination with
an adaptor for enabling a liquid solvent to be introduced from an
outlet of a filling device into the orifice of the cartridge,
wherein the adaptor comprises a first device-engaging portion
whereby to maintain the outlet of the filling device in fluid
communication with the orifice of the cartridge, and a second
portion for engagement with the cartridge, the said first and
second portions being connected to one another by a frangible
connection; and
(b) introducing the liquid solvent introduced into the cartridge
through the outlet orifice to dissolve the lyophilized drug,
wherein introduction of the solvent causes the piston to move
longitudinally.
Description
The present invention relates generally to hypodermic injection
devices, and is for use with needleless injectors in
particular.
Needleless injectors are used as an alternative to hypodermic
syringes for delivering liquid drugs and medicaments directly
through the patient's skin and into the tissues without using a
needle. Such injectors consist of a piston pump, drive by a spring
or gas, which ejects the drug through a small discharge orifice at
sufficient rate and pressure to pierce the skin and enter the
tissue through the hole thus formed.
In WO 95/03844, a needleless injector is disclosed which uses
efficient energy storage and release means to provide a very
compact and easy-to-use device, and the present invention is
intended primarily for use with that device, although of course it
could be adapted for use with alternative injectors. Ideally, a
needleless injector would be provided to the end user pre-filled
with the drug, self-powered, and ready for immediate use. The
pre-filling of the injector would preferably be done by the drug
manufacturer, thereby ensuring sterility, correct dose, and
conformity to the approved specification.
However, whilst this is perfectly feasible for liquid-stable drugs
such as heparin and some vaccines, for example, many drugs consist
of two components, e.g. a lyophilised drug and its solvent. These
drugs have a short shelf-life in liquid forms, and must be
re-constituted and used immediately. Other drugs, which may be
already in liquid form, are supplied in bulk to a pharmacy for
example, and the pharmacist may be required to load the drug into
the injector.
There is a long-standing requirement for a single dose disposable
needleless injector which may be externally filled, and many
inventions aim to provide external loading methods--e.g. WO89/08469
(Parsons). Most such devices are complicated and costly, and are
inconvenient to use. With the present trend towards single use
disposable needleless injectors, the filling device ought to be
very simple to use, and sufficiently inexpensive so that it may be
disposed of with the injector.
Another invention, by Lindmayer, U.S. Pat. No. 4,518,385, is for a
disposable syringe which is filled by the user in a conventional
manner. After filling, the hollow filling needle is removed or
broken off, and the syringe body is inserted into the power unit.
The syringe body becomes the needleless dispensing member, and thus
the syringe has a dual function. Although U.S. Pat. No. 4,518,385
does go some way in simplifying the loading process, there is still
a substantial requirement for the user to exercise skill and
judgement in using the device. Moreover, the syringe is intended
for use with a multiple use power unit or actuator, which is
complex and expensive.
The present invention seeks to overcome the limitations of prior
art injectors, and provides a simple adaptor for use with a
standard hypodermic syringe, which adaptor may be removed after
filling the injector together with the syringe. After use, the
adaptor covers the end of the needle to prevent or reduce
likelihood of pricking the user.
Thus, according to a first aspect of the invention there is
provided an adaptor for enabling a fluid to be introduced from an
outlet of a filling device into an orifice of a needleless injector
cartridge, comprising a first portion for engagement with the
cartridge, and a device-engaging second portion for engagement with
the filling device, whereby to maintain the outlet of the filling
device in fluid communication with the orifice of the cartridge,
the said first and second portions being connected to one another
by a detachable connection.
According to a second aspect of the invention there is provided a
needleless injector cartridge in combination with an adaptor for
enabling a fluid to be introduced from an outlet of a filling
device into an orifice of the cartridge, wherein the adaptor
comprises a device-engaging portion whereby to maintain the outlet
of the filling device in fluid communication with the orifice of
the cartridge, the said first and second portions being connected
to one another by a detachable connection.
With the syringe assembled to the needleless injector, the
injectate may be transferred into the cartridge from the syringe,
through the discharge orifice in the cartridge, thus to displace
the cartridge piston by hydraulic pressure. Stop means is
preferably provided to limit the displacement of the piston, so
that the amount of injectate transferred into the injector
cartridge is predetermined.
Another aspect of the invention is to provide for the
reconstitution of a lyophilised drug. In a preferred embodiment,
the lyophilised drug is stored in the drug cartridge between the
discharge orifice and piston, so that the introduction of a liquid
solvent through the orifice will dissolve the lyophilised drug and
displace the piston by hydraulic pressure to a pre-determined
stop.
The connection between the syringe guide and drug cartridge or
cartridge retainer is preferably provided by a frangible joint or
other detachable connection. After transferring the injectate, the
syringe is given a sharp sideways pull which causes the guide to
break away from the cartridge or its retainer at the frangible
joint. Preferably the needle is protected by remaining inside the
resilient seal, which itself remains attached to the syringe
guide.
The invention in its various aspects is capable of providing a very
safe, simple and convenient means of filling a pre-assembled,
self-powered needleless injector to a pre-determined volume, with
safe disposal of the filling syringe thereafter. The safety aspect
is enhanced if the hypodermic syringe needle is blunt.
A preferred embodiment will be described with reference to the
accompanying drawings, in which:
FIG. 1 shows a cross-section through a needleless injector
containing a lyophilised drug and hypodermic syringe assembled to
the injector;
FIGS. 2a and 2b show a resilient seal, in plan view and
longitudinal section, respectively;
FIG. 3 shows a cross-section through a needleless injector with a
hypodermic syringe attached, for filling the injector with a liquid
drug, which may be reconstituted;
FIG. 4 shows a needleless injector drug cartridge with integral
syringe guide; and
FIGS. 5a and 5b are general views of an injector before and after
filling.
For the sake of simplicity, like parts are given the same
numbers.
Referring to FIG. 1, a needleless injector body 1 contains a drug
cartridge 2 retained by a sleeve 3 having a threaded flange 18. The
cartridge 2 contains a lyophilised drug 5, preferably preformed to
fit closely to the internal container of the drug cartridge, and
held firmly in place by a piston 4, adjacent to a discharge orifice
23. A syringe guide 22 is frangibly attached by a frangible
connection 10 to the retaining sleeve 3. The syringe guide 22 is
preferably tubular, open at one end to receive a syringe 8, and
having a partial end wall 24. Inserted in a concentric hole in the
end wall 24 is a resilient seal 6 (see also FIGS. 2a and 2b) which
is biased to form an hydraulic seal around the discharge orifice 23
of the cartridge 2. Referring to FIG. 2, the resilient seal 6 has a
hole 11 to sealingly receive the hypodermic needle 7 (FIG. 1) of
the syringe 8, and may have circumferential ribs 12 to improve the
sealing efficiency on the cartridge 2. A conical entry hole 14
helps to guide the needle into the hole 11. Preferably, the conical
hole 14 is sealed with a frangible diaphragm 15, which may be made
from a laminate of aluminium foil and plastics, or other material
which is impervious to water vapour and capable of withstanding a
pressure differential of up to 900 mbar. Retaining lip 25 serves to
hold the seal 6 in the end wall 24 of the syringe guide 22 (FIG.
1).
Referring to FIGS. 1 and 2, the filled syringe 8 is loaded into the
open end of the syringe guide 22; the guide is long enough to align
the syringe body so that the needle 7 is approximately concentric
with the conical hole 14 in the seal 6. By pushing on the syringe
body, the needle 7 ruptures the frangible diaphragm 15, and is
guided by the conical hole 14 to enter the hole 11. The syringe
body comes to rest on a rim 19, which extends axially from the end
wall 24 of the syringe guide 22. The rim 19 may also locate the
seal 6, so that the end of the needle 7 just touches the orifice 23
in cartridge 2. The bore of the needle 7 is now in hydraulic
contact with the inside of the drug cartridge 2 via the orifice 23,
and by acting on the plunger of the syringe 8, solvent 9 will be
transferred into the drug cartridge 2. The hydraulic pressure
created within the syringe 8 causes the piston 4 to move in the
cartridge 2 until it stops at position 4a against an abutment 16
formed on the injector body. During this time, the turbulence of
the inflowing solvent 9 will agitate the lyophilised drug 5,
helping it to dissolve. An agitator (not shown) may be previously
loaded together with the drug 5, so that by shaking the needleless
injector after filling, rapid dissolution of the drug 5 will
result.
After filling the injector, the syringe 8 and guide 22, whilst
still assembled together, may be snapped off of retaining sleeve 3
at the frangible connection 10, by pulling it sharply sideways in
direction X relative to the injector, as shown in FIG. 5b.
Referring to FIG. 3, a similar construction to that already
described is shown, except that the drug container 2 does not at
this stage contain any drug (e.g. lyophilised drug) and the piston
4 is shaped to conform closely to the internal profile of the
discharge end of container 2. This embodiment is for use with a
hypodermic syringe, as before, but the drug to be transferred is
pre-mixed. A further enhancement shown in FIG. 3, and applicable to
all embodiments, is a resilient projection 26, extending from the
inside wall of the guide 22, which serves to prevent removal of the
syringe 8 from the guide 22 after insertion.
In the embodiments described, the drug cartridge is a separate
component, and may be made from glass, metal, or plastic. In order
to withstand the high pressure produced during injection, the
retaining sleeve 3 may act as a reinforcing member to the drug
cartridge 2, which then may be of a more lightweight construction
than otherwise possible.
A further embodiment is shown in FIG. 4, in which the drug
cartridge 2 is made with thread 18 for screwing directly on
injector body 1. This embodiment is preferably manufactured in a
plastics material, and the syringe guide 22 may be conveniently
moulded integrally with the cartridge 2, with the frangible
connection 10 between the two elements. If the material strength is
too low for a reasonable wall thickness to the cartridge, the
cartridge may be fitted with a reinforcing sleeve 17 either after
moulding, or as an insert during moulding. The abutment 16 may be
conveniently moulded on the cartridge 2, either as a continuous
ring or as small projections. Alternatively, the abutment may be an
interference-fit ring in the cartridge 2 to achieve the same
objective of limiting the stroke of the piston 4. Piston 4 is
configured to fit closely to the internal profile of the discharge
end of the cartridge 2. To avoid undue difficulties in moulding,
the resilient seal 6 may be retained in a separate holder 20, which
may be an interference fit or retained by cooperating lugs in the
guide 22, so as to bias seal 6 to form an hydraulic seal on the
discharge end of the cartridge 2. This embodiment may be adapted to
contain an lyophilised drug, similarly to the embodiment shown in
FIG. 1, and the piston 4 may be shaped with a flat end face.
A feature of all the embodiments described above is that the
hypodermic syringe 8 and its guide 22 are snapped off together
after filling the injector, and the seal 6 remains in situ in the
guide 22 to reduce the risk of injury from the end of needle 7.
This risk may be further reduced by having a blunt or rounded end
to the needle instead of the usual sharp point. Of course, it may
be that a commercial hypodermic syringe is inconvenient, if, for
example, more than one needleless injector is to be filled from a
large filled syringe. Such procedures may be necessary in hospitals
and pharmacies, where the injector is to be used within a short
time of filling. In these cases, the guide 22 is left in place and
the hole 11 in the seal 6 may be self closing after removal of the
filling needle 7, in order to maintain at least short term
sterility of the drug contained in the injector. When the injector
is required for use, the guide 22 is snapped off as previously
described, taking the seal 6 with it.
For all embodiments, the preferred material for piston 4 is PTFE or
similar fluoropolymer having a compressive strength that is highly
dependent on the rate of application of force at room temperature.
Thus the piston 4 may easily deform when pushed past the abutment
16 (FIG. 4) and spring back to seal on the walls of the cartridge
2, but when the injection force is applied at a high rate to the
piston 4, it has insufficient time to deform and will maintain its
sealing properties throughout the injection.
Whilst the embodiments described specify screw thread means of
retaining the drug cartridge onto the injector body, it would be
equally feasible to use snap-fit retaining means. Furthermore, the
retaining means may use cut-outs or other mechanical keying means
to ensure the correct matching of drug cartridge to injector body.
It is preferred that the drug cartridge is not easily removed from
the injector power unit after performing an injection, except by
means of a tool.
Many variations of the basic invention are possible. For example,
the injector and syringe may be supplied as part of a kit with
which the user must reconstitute a lyophilised drug for self
administration. The syringe containing the solvent may be
pre-inserted in the syringe guide, so that the user merely has to
push the syringe slightly further into the guide to break the seal,
and operate the syringe plunger until the solvent ceases to be
transferred, that is, when the injector piston reaches the abutment
in the cartridge.
It may be seen therefore that the present invention enables a
needleless injector to be filled with the absolute minimum of
skill, using a very inexpensive and familiar hypodermic syringe or
similar device.
* * * * *